1. Technical Field
The present disclosure relates to a signal observation device using compressed sensing.
2. Description of the Related Art
In recent years, a signal observation technique using compressed sensing is attracting attention. This compressed sensing is also called compressed sampling or sparse sampling. The compressed sensing is a technique that makes it possible to restore an original signal from a signal acquired with the number of samples that is equal to or lower than the sampling theorem under a condition that the signal is sparse and is a technique that acquires and compresses a signal concurrently.
The expression “signal is sparse” means that many coefficients become almost 0 when the signal is projected to a wavelet space, a discrete cosine space, or the like. A method such as L1 norm minimization is used as a signal restoration method utilizing sparsity of a signal (see, for example, Toshiyuki TANAKA “Mathematics of Compressed Sensing”, The Institute of Electronics, Information and Communication Engineers, Engineering Sciences Society, Fundamental Review Vol. 4 No. 1, Jul. 2010 (pp. 39-47) (hereinafter referred to as “Non-Patent Literature 1”)).
Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2015-510356 (hereinafter referred to as “Patent Literature 1”) discloses lens-free image acquisition using compressed sensing. In the image acquisition of Patent Literature 1, light reflected by a subject is selectively delivered onto a single detector by using a shutter array. By performing such light detection plural times, a high-resolution image is acquired by the detector.